Back rest arrangement

Abstract

The invention relates to a back rest arrangement, in particular for an office chair, comprising a deformable back rest extending in vertical (H) and transverse direction (Q) comprising a lordosis support region that can be adjusted in terms of height and curvature, wherein an adjustment device for adjusting the height and the curvature of the lordosis support region is arranged on the back rest support arm in an adjustable manner in terms of height and wherein the adjustment device is connected to the back rest on fastening arms protruding in the transverse direction (Q) by means of bearings comprising counter bearings on the back rest side.

1 . A backrest arrangement comprising a deformable backrest which extends in the vertical direction (H) and transverse direction (Q) and comprises a lordosis support region, the height and curvature of which can be adapted, a backrest supporting arm, wherein the backrest is connected to the backrest supporting arm on an upper fastening element, and an adjustment device for adapting the height and curvature of the lordosis support region, which adjustment device is arranged on the backrest supporting arm so as to be adjustable in height and wherein the adjustment device is connected to the backrest, by means of bearings having backrest-side counter-bearings, on fastening arms projecting in the transverse direction (Q). 
     
     
         2 . The backrest arrangement according to  claim 1 , wherein the adjustment device comprises a catch device which is movable up and down from a catch position into an adjustment position and is actuable from the catch position into the adjustment position by means of an actuating arm, whereby the height of the adjustment device can be adapted along slide bearings in such a way that the height and curvature of the lordosis support region can be changed automatically by displacing the adjustment device. 
     
     
         3 . The backrest arrangement according to  claim 2 , wherein the adjustment device comprises a preferably bridge-like bearing bracket which comprises the slide bearing and the bearing bracket is connected to the fastening arms, with the formation of an opening, and the backrest supporting arm being guided, by a slide bearing portion, through the opening. 
     
     
         4 . The backrest arrangement according to  claim 1 , wherein the fastening arms each form a bearing portion at the ends thereof for fastening the backrest-side bearing to the backrest. 
     
     
         5 . The backrest arrangement according to  claim 1 , wherein the backrest supporting arm is formed substantially in an S-shape. 
     
     
         6 . The backrest arrangement according to  claim 1 , wherein the bearings are fastened laterally to lateral surfaces of the backrest. 
     
     
         7 . The backrest arrangement according to at least one  claim 4 , wherein the end bearing portions of the fastening arms engage laterally around the backrest at least in part. 
     
     
         8 . The backrest arrangement according to  claim 2 , wherein the actuating arm extends substantially in parallel with one of the fastening arms and an actuating portion that is accessible to the chair user between the fastening arm and the backrest is located at the end of the actuating arm for releasing the actuating arm from its catch position. 
     
     
         9 . The backrest arrangement according to  claim 1 , wherein the backrest supporting arm is connected to a spring device by means of a connecting plate for fastening the backrest arrangement to a seat carrier in a spring-loaded manner. 
     
     
         10 . The backrest arrangement according to  claim 9 , wherein the spring device comprises a helical spring, the spring force of which can be adapted. 
     
     
         11 . The backrest arrangement according to  claim 10 , wherein the helical spring extends from the connecting plate in the vertical direction (H) around a threaded rod and an adaptation device is attached to the lower end of the threaded rod in order to be able to adapt the spring force of the helical spring. 
     
     
         12 . The backrest arrangement according to at least one  claim 10 , wherein the connecting plate is clamped against a top side, which forms a bearing surface, of the seat carrier by the helical spring. 
     
     
         13 . The backrest arrangement according to at least one  claim 9 , wherein the spring device comprises a vertically movable journal bearing having a cylindrical opening around the threaded rod, and said journal bearing is connected to the connecting plate. 
     
     
         14 . A backrest arrangement comprising a deformable backrest and a backrest supporting arm, wherein the backrest is connected to the backrest supporting arm on an upper fastening element and wherein the lower fastening end of the backrest supporting arm is formed with a spring device by means of a connecting plate for arranging the backrest arrangement in a spring-loaded manner against the top side of a seat carrier attached to the chair. 
     
     
         15 . The backrest arrangement according to  claim 1 , wherein the backrest comprises an elastically deformable backrest pad. 
     
     
         16 . The backrest arrangement according to  claim 1 , wherein said backrest arrangement is for an office chair. 
     
     
         17 . The backrest arrangement according to  claim 14 , wherein said backrest arrangement is for an office chair. 
     
     
         18 . The backrest arrangement according to  claim 14 , wherein the backrest comprises an elastically deformable backrest pad.